Revised GRASP with path-relinking for the linear ordering problem

The linear ordering problem (LOP) is an NP\mathcal{NP}-hard combinatorial optimization problem with a wide range of applications in economics, archaeology, the social sciences, scheduling, and biology. It has, however, drawn little attention compared to other closely related problems such as the quadratic assignment problem and the traveling salesman problem. Due to its computational complexity, it is essential in practice to develop solution approaches to rapidly search for solution of high-quality. In this paper we propose a new algorithm based on a greedy randomized adaptive search procedure (GRASP) to efficiently solve the LOP. The algorithm is integrated with a Path-Relinking (PR) procedure and a new local search scheme. We tested our implementation on the set of 49 real-world instances of input-output tables (LOLIB instances) proposed in Reinelt (Linear ordering library (LOLIB) 2002). In addition, we tested a set of 30 large randomly-generated instances proposed in Mitchell (Computational experience with an interior point cutting plane algorithm, Tech. rep., Mathematical Sciences, Rensellaer Polytechnic Institute, Troy, NY 12180-3590, USA 1997). Most of the LOLIB instances were solved to optimality within 0.87 seconds on average. The average gap for the randomly-generated instances was 0.0173% with an average running time of 21.98 seconds. The results indicate the efficiency and high-quality of the proposed heuristic procedure.     

The Impact of Rainfall on the First Out-Migration: A Multi-level Event-History Analysis in Burkina Faso

Using event history analyses, we investigate the impact of rainfall conditions — a crucial environmental factor in the livelihood of Sahelian households— on the risk of the first village departure in Burkina Faso. The distinction of migrations by destination and duration proves critical in studying this relationship. Findings suggest that people from the drier regions are more likely than those from wetter areas to engage in both temporary and permanent migrations to other rural areas. Also, short-term rainfall deficits tend to increase the risk of long-term migration to rural areas and decrease the risk of short-term moves to distant destinations.     

Does Weighting Capture What’s Important? Revisiting Subjective Importance Weighting with a Quality of Life Measure

The present study evaluated subjective importance weighting using data collected with the Injection Drug User Quality of Life Scale (IDUQOL). Weighted and unweighted IDUQOL scores from 241 adults were correlated with convergent, discriminant, and criterion measures. Regression analysis was used to examine the contribution of importance ratings to scores on a global measure of life satisfaction and the corrected weighted IDUQOL total scores. Overall, the results showed that weighted scores did not perform better than unweighted scores in measuring quality of life. However, the mean satisfaction ratings for important domains correlated significantly higher with convergent measures than did the mean satisfaction ratings for unimportant domains. This finding suggests further attention needs to be paid to the meaning and measurement of subjective importance and how it may be incorporated more effectively into measures of quality of life.     

Contents of Volume 68

Volume Contents

Contents of Volume 68     

Formal pooling of health risks in sub-Saharan Africa: Reflections on the obstacles encountered

Over the past few years a number of institutional solutions to the pooling of health risks have been advanced in a great number of reform proposals for developing countries. The empirical arguments in favour of such recommendations have the full force of accumulated experience in countries that have long been industrialized. However, rural realities in Africa and Asia naturally have very little to do with past or present realities in western countries. Whereas the technical-cooperation and scientific community has relatively good knowledge of techniques, a number of recent experiences of the introduction of mutual benefit schemes in Africa seem to show that this approach is now enjoying some success. The low levels of membership in particular make it essential to tackle the problem fully. This article tries to identify the various possible explanations for this lack of enthusiasm in sub-Saharan Africa.     

Impact Evaluation of a Cognitive Behavioral Group Therapy Model in Brazilian Sexually Abused Girls

This study evaluated the impact of a cognitive behavioral group therapy model in Brazilian girls who had experienced sexual abuse. The effect of the waiting period before treatment and the enduring effectiveness of the treatment after six and 12 months were also evaluated. Forty-nine female sexual abuse victims between the ages of 9 and 16 completed instruments measuring depression, anxiety, stress, and post-traumatic stress disorder before, during, and after the group therapy. The group therapy had a positive impact on their psychological functioning, significantly reducing symptoms of anxiety, stress, and post-traumatic stress disorder. The therapeutic effects lasted six to 12 months after the treatment ended. The model proved effective for treating young female victims of sexual abuse.     

The use of population‐level data to advance interdisciplinary methodology: a cell‐through‐society sampling framework for child development research

The authors argue that population‐level data should be used to advance interdisciplinary research about community effects on early development. These data permit the identification of neighborhoods in which development patterns deviate from predictions based on local socioeconomic status (SES). So‐called ‘off‐diagonal’ places signal where researchers are likely to discover processes that either deflect the risks of low SES or dampen the salutary impact of favorable SES. Since such neighborhoods will be best understood relative to nearby ‘on‐diagonal’ neighborhoods where macro‐economic and/or public policy factors are constant, the authors present a methodology for illuminating these regional clusters. The method is deployed in British Columbia, Canada, where a team has collected developmental observations from two censuses of kindergarten children (n = 82,632). The article discusses how these clusters can be used to coordinate sampling decisions among academics representing the range of disciplines needed to study child development from cell‐through‐society, as is recommended in the literature.     

It Takes Two to Tango: Couples’ Happiness and Childbearing

The existing literature has so far considered the role of the individual’s subjective well-being on fertility, neglecting the importance of the partner’s well-being. Using data from the British Household Panel Survey (BHPS) and event history models estimated separately by parity, we find that in a couple, women’s happiness matters more than that of the male partner in terms of having the first child. Specifically, we observe that couples in which either partner is happier than usual are more at risk of having the first child, but the effect is stronger with higher happiness of the woman. For the transition to the second child, we find that couples in which the woman declares to be happier or less happy than usual have a lower risk of childbirth. We, moreover, find support for a multiplicative effect of partners’ SWB on the decision to have a first child. Our results show that failing to acknowledge that the subjective well-being of both partners matters for the inherently joint decision making of childbearing can lead to an incomplete view of how subjective well-being affects fertility.